Size-dependent polarization distribution in ferroelectric nanostructures: Phase field simulations

From phase field simulations, we investigate the size-dependent polarization distribution in ferroelectric nanostructures embedded in a nonferroelectric medium. The simulation results exhibit that vortex structures of polarizations and single-domain structures are formed in ferroelectric nanodots and nanowires, respectively. Furthermore, a single-vortex structure is formed in the ferroelectric nanodots if the aspect ratio of thickness to lateral size is less than a critical value, whereas the ferroelectric nanodots are in a multivortex state if the aspect ratio exceeds the critical value. When the aspect ratio approaches infinity, nanodots will become nanowires, in which polarizations are homogeneous. (c) 2008 American Institute of Physics.